PROOFS OF THE PROPERTIES OF OXIGEN GAS.

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DECOMPOSITION OF OXIGEN GAS BY METALLICSUBSTANCES.

Oxigen has likewise a great affinity for another kind of com-bustible bodies, we mean those called metals ; particularly whenheated to a certain degree. All metallic bodies, except gold,silver, and platina, have the property of decomposing oxigengas, by attracting its ponderable basis (the solid oxigen) fromthe caloric and light, which kept it in its gazeotts state. Theythen lose their qualities and approach to the acid state.

Experiment I.

Comlustion of iron in origm gas.

This experiment may be exhibited in the most convenientmanner as follows : a glass receiver, with a narrow open neck,must be provided. It may be closed at the top with a cork, ora rough-ground flat piece of glass or metal. It is to be filled

■with water and put upon the shelf of the pneumatic trough.

Oxigen gas is then conveyed into it in the usual manner.When the receiver is filled with gas, a shallow bason or dish withwater must be brought near it, so that the receiver may be re-moved with the gas, and easily slid into the bason. The gas isthus confined by the water and the receiver may be removed to

any convenient place. Iron wire of about ^ of an inch in

diameter must be coiled tightly round a stick of wood or glass ofabout half an inch in diameter; die stick is then withdrawnand the wire will form a length of spiral rings. This wire,extended to about die inside length of the receiver, must befixed in a cork so that it may hang vertically, and may be rea-dily introduced at the top of the receiver and kept by meansof the cork, firm therein; at the other extremity of the wirea litde thread dipped in sulphur, or a piece of wood is to be